Arthur Berman, an oil analyst with Labyrinth Consulting Services, says the promise of America's shale reserves have been vastly overstated.

His main argument: Shale is too expensive to drill, and shale wells usually don't last longer than a couple of years.

Last year, he laid out his case at a gathering of the Association for the Study of Peak Oil and Gas in Austin Texas.

With his permission, we've reproduced it here.

Berman argues the promise of America's shale revolution is "magical thinking." Shale drilling is too expensive and too ephemeral to make a lasting impact.

Arthur Berman

There tends to be a huge gap between the estimated amount recoverable and what actually ends up getting recovered.

Arthur Berman

Shale is the most expensive and most complicated source of energy.

Arthur Berman

The amount of product shale has contributed to overall consumption has been relatively minuscule.

Arthur Berman

The gap between production and consumption is 9 million barrels of oil a day. "It is unlikely that the U.S. will become energy independent," Berman argues.

Arthur Berman

Berman focuses on the Bakken oil play in North Dakota. As of last summer it had 236 rigs, second highest in the nation.

Arthur Berman

He says Bakken oil production has increased to 573,000 barrels per day from 4874 producing wells. The average well is 118 barrels of oil per day, and each well costs $11.5 million.

Arthur Berman

But the Bakken has a 38 percent decline rate, according to Berman — meaning if you stopped drilling now, you'd lose 38% of your production after a year.

Arthur Berman

He says there was no improvement in well efficiency between 2010 and 2011. In some cases it's taking increasing numbers of wells to get the same amount of product. Berman says the costs are "astronomical."

Arthur Berman

The Bakken is already going at a breakneck rate — there's now very little production coming from wells older than a few years.

Arthur Berman

We can see the same phenomenon occurring in other shale plays like the Eagle Ford in Texas.

Arthur Berman

The number of currently viable wells in the Bakken has dwindled.

Arthur Berman

In conclusion: America's gains from shale will be short-lived, and certainly won't be our bridge to independence.